Patents Pending

Not Yet Published Color-based Cache Monitoring

D. Bacon, O. Krieger, X. Shen, R. Wisniewski
IBM docket YOR920050452US1, filed 5 January 2007.

Techniques for providing information to run-time systems about cache traffic on a multiprocessor.

Patent (PDF) System and Method for Concurrent Garbage Collection

D. Bacon, P. Cheng, D. Grove, M. Vechev
United States Patent Application US 2007/0022149 A1, published 25 January 2006.

Generalizations of garbage collection techniques as described in the ECOOP'05 paper.

Patent (PDF) Generational Real-time Garbage Collection

D. Bacon, P. Cheng, D. Grove, M. Vechev
United States Patent Application US 2006/0294165 A1, published 28 December 2006.

Generational real-time collection via synchronous nursery collection, as described in the LCTES'05 paper.

Patent (PDF) System and Method for Managing Data

D. Bacon, P. Cheng, D. Grove
United States Patent Application US 2006/0106986 A1, published 18 May 2006.

Hardware support for adaptive compression of pointers and data using a hardware look-aside buffer.

Patent (PDF) Method and Program for Space-efficient Representation of Objects in a Garbage-collected System

D. Bacon, P. Cheng, D. Grove
United States Patent Application US 2006/0085433 A1, published 20 April 2006.

Method for performing sliding compaction without extra metadata.

Patent (PDF) Breaking Read Barrier to Apply Optimizations

D. Bacon, P. Cheng, and V. Rajan
United States Patent application US 2005/0149587 A1, published 7 July 2005.
Docket number YOR9-2003-0177, filed 15 December 2003.

In the Metronome, breaking up the steps of a read barrier allows the application of optimizations which leacd to greatly reduced read barrier overhead.

Patent (PDF) Method and Apparatus for Optimizing Away a Null Check

D. Bacon, P. Cheng, and V. Rajan
United States Patent application US 2005/0149588 A1, published 7 July 2005.
IBM Docket number YOR9-2003-0178, filed 15 December 2003.

In the Metronome the null check associated with a read barrier can be optimized away by "sinking" the check to the first reference to the pointer, at which point the system performs an implicit null check, usually using a hardware trap with no overhead when not triggered.

Patent (PDF) Garbage Collector with Eager Read Barrier

D. Bacon, P. Cheng, and V. Rajan
United States Patent application US 2005/0149589 A1, published 7 July 2005.
Docket number YOR9-2003-0179, filed 15 December 2003.

Read barriers have typically been "lazy", that is, they are applied when a pointer is used. In the Metronome pointers are forwarded eagerly, greatly reducing the overhead, as when an array pointer is used in a loop.

Patent (PDF) Method and Apparatus for Scheduling and Performing Garbage Collection in a Real-time System with Guaranteed Space Bounds

D. Bacon, P. Cheng, and V. Rajan
United States Patent application US 2005/0149585 A1, published 7 July 2005.
Docket number YOR9-2003-0181, filed 15 December 2003.

Method used in the Metronome to ensure that the time-based scheduling of the incremental collector meets the space bounds set for the system.

Patent (PDF) Method and Apparatus for Efficient Implementation of Discontiguous Objects

M. Arnold, D. Bacon, P. Cheng, and V. Rajan
United States Patent application US 2005/0149346 A1, published 7 July 2005.

Optimizations of arraylets that allow indirections to be avoided in most cases.


Disclosures

Not Available Lazy Generation of Hash Codes in a Garbage Collected System

D. Bacon and M. Wegman
Abandoned due to prior art.

Technique for representing a hash code with only two bits per object.